1. Field of the Invention
The present invention relates to a zoom lens and an imaging apparatus. In particular, the present invention relates to a zoom lens appropriate for a digital camera, a video camera or the like using an imaging device, such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor), and an imaging apparatus including the zoom lens.
2. Description of the Related Art
In recent years, as personal computers spread to ordinary families, digital cameras that can input image information, such as a landscape and a portrait, obtained by photography to personal computers became widely used. As a lens system, a zoom lens is mainly used in such a digital camera. Recently, a request for reducing the size of a camera is increasing in addition to a request for increasing the magnification ratio of zoom.
Conventionally, lenses disclosed, for example, in Japanese Unexamined Patent Publication No. 9 (1997)-230237 (Patent Document 1), Japanese Unexamined Patent Publication No. 2010-217228 (Patent Document 3), Japanese Unexamined Patent Publication No. 2005-181635 (Patent Document 3), and Japanese Unexamined Patent Publication No. 2009-198722 (Patent Document 4) are known as a zoom lens for a camera consisting of five groups. Among them, Patent Documents 2 through 4 disclose lenses constituting bending optical systems, in which an optical path is bent at some point in the optical path. Patent Document 1 discloses a zoom lens structured in such a manner that all of five lens groups are moved during changing magnification. Patent Document 2 discloses a zoom lens, in which a fifth lens group is a positive lens group, and a second lens group consists of three lenses of a negative lens, a negative lens, and a positive lens in this order from the object side. Patent Documents 3 and 4 disclose zoom lenses in which a second lens group consists of four lenses of a negative lens, a negative lens, a positive lens, and a negative lens arranged in this order from the object side.